The invention relates in particular to a device for coupling shopping carts, suitcase carriers and the like with one another or with a fixed electric supply. The device includes a disengageable clutch formed of a trap and a clutch member for selective detachable coupling of the shopping carts in a space-saving stacked position, and of a coin operated catch by which, when fitting the shopping carts together, a clutch member attached to a shopping cart is engageable with the trap provided on the adjacent shopping cart and the coin is stopped when the clutch is disengaged and is released only after renewed coupling together.
A similar device is known from German OS No. 31 27 940. Here the coupling member is a rigid bar-like part which projects from a housing attached to the shopping cart in the lower region thereof and can be introduced automatically into a socket part on the opposite side at an adjacent shopping cart. In this way shopping carts can indeed be secured, in that the clutch is released only when by means of a coin an unlocking means is actuated; however, inserting the clutch members into the socket parts often entails considerable difficulties. Since the clutch and socket parts must have the same height position for them to be pushed one into the other, coupling may sometimes not be possible on uneven ground and special guide means are required for height equalization. But especially it is a disadvantage that by the rigid clutch members any vibration, caused in particular by the coupling of a shopping cart or by its removal, is transmitted to all circuit elements of the coupled carts and, in order to prevent any automatic release caused thereby, a protective resistance must be provided. Such protective resistances consume much current continuously, so that the operating costs are relatively high and also the contacts are under heavy stress. Therefore, despite the high cost of construction, smooth operation for a protracted period is not ensured with this safety means.